Although it is now nearly twelve years since I left India, my interest has not abated in the scenes and subjects of former labours in that country, and I am still careful to note anything which is published in reference to them. This practice enabled me to add some facts to the history of the two above-named volcanoes in my Second Notice, besides quoting from the account by Mr. F. R. Mallet, the principal results of his survey made in conjunction with Captain Hobday, eleven years after my visit to them, which took place in the year 1873.

In my recently published book on the “Glacial Nightmare” I have tried, among other things, to show that the traces of glacial action in the northern hemisphere, instead of being circumpolar, are in fact limited to one half only of the hemisphere, namely, that bounded on the East by the White Sea and on the West by the river Mackenzie. This conclusion is of course not new, and I have merely collected and condensed the evidence of many witnesses to it. I have further suggested as possible, that while Scandinavia, Finland, and the British Islands were the homes of very large and extensive glaciers, the lands now occupying the Polar Sea were in a very different condition, and anything but the homes of widespread ice action.

It is one of the most fascinating of the recreations of a geologist to attempt to reconstruct the physical features of some past period; and though our essays in this direction have not been attended with complete success, and our maps of early epochs bear a striking resemblance to those of Herodotus and Ptolemy, yet thesemaps have their value and they are at least steps towards one of the goals of the science of geology.

Mr. G. Abbott is quite right in saying (Geol. Mag. for June, p. 275) that much work has yet to be done before we understand the formation of flints, and I would add that the work required must include observations on other siliceous concretions such as chert and cherty nodules of all kinds. It is also unquestionably important that we should, if possible, ascertain whether such concretions were formed contemporaneously with the deposits in which they are now found, or whether they are a sort of separation product formed during the consolidation of the rock after upheaval above the sea.

Mr. Charles Schuchert of Newhaven, Conn., U.S.A., has recently published in the “American Geologist” (Vol. xi.No. 3) an important and highly suggestive “Classification of the Brachiopoda,” based on the history of the class (Chronogenesis) and the ontogeny of the individual. It embodies the latest results of the remarkable investigations on the Palaeozoic forms of Prof. James Hall and Mr. J. M. Clarke, who have thrown so much light on the evolution of genera among the Brachiopoda in the eighth volume of “The Palæontology of New York” (Part I. Brachiopoda, 1892).

At St. Anne's-on-the-Sea, Lancashire, there are a great number of very large sand-hills. They are for the most part crateriform in the centre, from the gyratory movement of the wind in stormy weather. There must be some cause, however, which determines the course of the wind, for its natural action one would suppose should be to carry away dunes by sweeping them before it.